除了吞沒地面和改變美國東南部的生態(tài)系統(tǒng)，葛還可能增加該地區(qū)的臭氧污染,。這種亞洲入侵植物是在20世紀(jì)早期種植的,，原本用于幫助控制侵蝕。它是一種快速生長的豆科植物,，以很高的速率固定大氣中的氮,。由于固氮植物的入侵可能影響到土地和大氣環(huán)境，Jonathan Hickman及其同事通過比較沒有受影響以及被葛入侵的土壤的氮流量,，從而調(diào)查了葛對于該地區(qū)的空氣質(zhì)量的影響,。
這組科學(xué)家報告說，氮氧化物（臭氧的前體）的排放在被入侵土壤中幾乎加倍,。這組作者使用了一種化學(xué)運輸模型預(yù)測了氮氧化物增加的效應(yīng),，并且提出了一種情景,，即和沒有葛的情景相比，該地區(qū)的一些地方的高臭氧天數(shù)隨著葛的入侵加劇而增加了35%以上,。這組科學(xué)家提出,，這項研究確立了入侵植物和臭氧形成之間的一個可測量的聯(lián)系。這組作者說,，除了它對地面的視覺影響以及它影響環(huán)境變化的潛力,，葛的生存范圍也可能隨著全球溫度增加而擴(kuò)展。(生物谷Bioon.com)
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.0912279107
Kudzu (Pueraria montana) invasion doubles emissions of nitric oxide and increases ozone pollution
Jonathan E. Hickmana,1,2, Shiliang Wub,3, Loretta J. Mickleyb, and Manuel T. Lerdauc
The nitrogen-fixing legume kudzu (Pueraria montana) is a widespread invasive plant in the southeastern United States with physiological traits that may lead to important impacts on ecosystems and the atmosphere. Its spread has the potential to raise ozone levels in the region by increasing nitric oxide (NO) emissions from soils as a consequence of increasing nitrogen (N) inputs and cycling in soils. We studied the effects of kudzu invasions on soils and trace N gas emissions at three sites in Madison County, Georgia in 2007 and used the results to model the effects of kudzu invasion on regional air quality. We found that rates of net N mineralization increased by up to 1,000%, and net nitrification increased by up to 500% in invaded soils in Georgia. Nitric oxide emissions from invaded soils were more than 100% higher (2.81 vs. 1.24 ng NO-N cm?2 h?1). We used the GEOS-Chem chemical transport model to evaluate the potential impact of kudzu invasion on regional atmospheric chemistry and air quality. In an extreme scenario, extensive kudzu invasion leads directly to an increase in the number of high ozone events (above 70 ppb) of up to 7 days each summer in some areas, up from 10 to 20 days in a control scenario with no kudzu invasion. These results establish a quantitative link between a biological invasion and ozone formation and suggest that in this extreme scenario, kudzu invasion can overcome some of the air quality benefits of legislative control.
